High-power and low-noise 1.55 μm InP-based quantum dash lasers

The explosion of internet traffic, the increase in data or multimedia transmission are the main reasons for a huge rise in demand for transmission bandwidth especially in dense wavelength division multiplexing (DWDM) systems. Nowadays this technique must be developed in the 1.4 μm to 1.65 μm wavelength range to follow the progress of new low-loss fibres. A decade ago, a new class of gain material, based on quantum dot was intensively studied. For three years, researchers have succeeded in growing new elongated nano-structures based on InP, called quantum dashes, for applications beyond the wavelength limit of 1.3 μm using GaAs-based quantum dots. These great strides in the elaboration of these new gain materials could meet this gain bandwidth. In the framework of the European project, BIGBAND, we have developed 1.55 μm quantum dash Fabry-Perot lasers based on InP using a ridge waveguide operating in continuous wave at room temperature. These devices have reached the power of 40 and 50mW per facet in p side up and down configurations respectively and have shown a low relative intensity noise (RIN) of -162 dB/Hz ± 1.6 dB in 0.1-13 GHz range.